Answer:
Add 3/4 to both sides (the last option)
Step-by-step explanation:
Since you want to isolate f and the expression on one side is f - 3/4, you have to add 3/4 so that the -3/4 cancels out. When you do that, you also have to add 3/4 to the other side so that the equation stays balanced.
2(x-6)(x+9)
